Commits
Ed Cashin committed 7135a71b19b
aoe: allocate unused request_queue for sysfs Andy Whitcroft reported an oops in aoe triggered by use of an incorrectly initialised request_queue object: [ 2645.959090] kobject '<NULL>' (ffff880059ca22c0): tried to add an uninitialized object, something is seriously wrong. [ 2645.959104] Pid: 6, comm: events/0 Not tainted 2.6.31-5-generic #24-Ubuntu [ 2645.959107] Call Trace: [ 2645.959139] [<ffffffff8126ca2f>] kobject_add+0x5f/0x70 [ 2645.959151] [<ffffffff8125b4ab>] blk_register_queue+0x8b/0xf0 [ 2645.959155] [<ffffffff8126043f>] add_disk+0x8f/0x160 [ 2645.959161] [<ffffffffa01673c4>] aoeblk_gdalloc+0x164/0x1c0 [aoe] The request queue of an aoe device is not used but can be allocated in code that does not sleep. Bruno bisected this regression down to cd43e26f071524647e660706b784ebcbefbd2e44 block: Expose stacked device queues in sysfs "This seems to generate /sys/block/$device/queue and its contents for everyone who is using queues, not just for those queues that have a non-NULL queue->request_fn." Addresses http://bugs.launchpad.net/bugs/410198 Addresses http://bugzilla.kernel.org/show_bug.cgi?id=13942 Note that embedding a queue inside another object has always been an illegal construct, since the queues are reference counted and must persist until the last reference is dropped. So aoe was always buggy in this respect (Jens). Signed-off-by: Ed Cashin <ecashin@coraid.com> Cc: Andy Whitcroft <apw@canonical.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Bruno Premont <bonbons@linux-vserver.org> Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>